Covering

ABSTRACT

A method of preparing a seamless carpetlike floor covering comprising applying a layer of a solvent-free liquid two component plastic system of resin and hardener to an inside floor or wall of a building, electrostatically spraying fiber flocking material onto the plastic system before it hardens, and hardening the plastic system with the flock material imbedded therein.

United States Patent 1 1 Keller COVERING [75] Inventor: Peter Keller,Hiltrup/Westf.,

Germany [73] Assignee: Glasurit-Werke M. Winkelmann A.G.,Hamburg-Wandsbek, Germany [22] Filed: Dec. 16, 1971 [21] Appl. No.:208,900

Related US. Application Data [63] Continuation of Ser. No. 803,433, Feb.28, 1969,

abandoned.

[30] Foreign Application Priority Data Mar. 8, 1968 Austria 2316/68 52Us. 01......' 117/17, 117/33 [51] B055 5/02 [58] Field of Search 117/17,33

[56] References Cited UNITED STATES PATENTS 3,496,911 2/1972 Chmelar118/621 2,776,223 ll/1957 Brown et al. 117/33 2,777,977 1/1957 Everand317/262 2,784,630 3/1957 Koprow et a]. 117/33 2,829,124 4/1958 Napravnik117/33 3,098,755 7/1963 Barth et al. 117/33 3,336,149 8/1967 Fox et al117/33 3,690,914 9/1972 Andreski 117/21 FOREIGN PATENTS OR APPLICATIONS948,988 2/1964 Great Britain 117/33 OTHER PUBLICATIONS Skeist, Handbookof Adhesives Rheinhold Publishing Corp., N.Y., 1962, pages V, VI, 286,287, 333,334.

Kirk and Othmar, Encyclopedia of Chemical Technology Vol. 8, pp.306-309, (1965).

Product Engineering Magazine June 19, 1967, pg. 1233.

Encyclopedia of Polymer Science & Technology, Vol. 6, page 241 (1967) &Vol. 7, pages 91 & 92 (1968).

Primary Examiner-William D. Martin Assistant Examiner-M. Sofocleous gAttorney, Agent, or Firm-Gilbert L. Wells; Krafft & Wells 57] ABSTRACT Amethod of preparing a seamless carpetlike floor covering comprisingapplying a layer of a solvent-free liquid two component plastic systemof resin and hardener to an inside floor or wall of a building,electrostatically spraying fiber flocking material onto the plasticsystem before it hardens, and hardening the plastic system with theflock material imbedded therein.

1 Claim, N0 Drawings COVERING The present application is a continuationof Application Ser. No. 803,433, filed Feb. 28, 1969, and now abandoned.

THE FIELD OF THE INVENTION ering floors. It is known that jute fabrics,after being coated with adhesive, can be flocked electrostatically withtextile fibers. In this manner a tufted carpet is obtained which issuitable for covering floors. By dispensing with the supporting fabrics,it has also been possible to deposit textile fibers directly upon apolyvinyl chloride paste in such a manner that after gelling of theflock-covered paste, carpet-like lengths or sheets will be obtainedwhich can be placed upon or adhered to floors. In order to obtain aclosed surface by welding together the adjacent pieces at their edges,the method disclosed in the German Pat. No. 949,261 may be used wherethe adjoining edges are coated with selfhardening synthetic resins suchas polyester resins, preferably mixed with fillers, casting resin orstyrene resin, and are then smoothed and polished. The polyester resinscan also be used in combination with diisocyanates.

These methods all have the disadvantage of first requiring the carpetcovering to be produced, which then, in a separate operation, has to beplaced on the floor. If textile fabrics are used as carriers for theapplied flock, then such coverings cannot be cleaned with soft soap andalkaline cleansing agents because such textile materials are sensitiveto water. Tufted carpets of this kind are also not compatible withfat-dissolvingagents which would loosen the resins.

The use of polyvinyl chloride pastes requires expensive heat treatmentand elaborate drying installations. Tuftedcarpets produced withpolyvinyl chloride as a carrier have the disadvantage of only limitedresistance to heat, chemicals and mechanical abuse.

Another serious difficulty with the production of flocked carpetcoverings is that only those adhesives can be used which have goodelectrical conductivity.

Since the carrier substances are usually good electrical insulators, theadhesive film has to be grounded during flocculation. If the electricityis not conducted away quickly enough, then there will be formed over theflocculated surface an opposing electric field which will disturbfurther flocculation and will lead to undesired difficulties. Anotherdifficulty with the usual process is that after the flock has beendeposited, the excess has to be removed. This is usually done bybrushing it away after the drying operation. If synthetic resins areused, and especially with polystyrene sheets, such removal is rendereddifficult by the tendency of the synthetic resin to acquire a strongelectrostatic charge resulting from friction, which will tend to retainthe excess flock that is to be removed.

Still another disadvantage is the usual necessity of leveling the floor,as by troweling, in preparation for laying the carpet.

It is indeed already known to deposit seamless synthetic resin floorcovering in a single layer and of sufficient thickness upon a floor,without requiring the floor to be leveled, when a solid thermoplasticsynthetic resin is mixed with fillers and heated until the mixturebecomes flowable or sufficiently soft to be roller troweled. Asubsequent flocking of fibers upon such a surface is not, however,possible after the surface has hardened.

Floor coverings are also disclosed in Swiss Pat. No. 361,1 14 whichconsist ofa coating of duroplastic under polyadditions of hardenedsynthetic resins, one component of which is an unsaturated polyesterresin. To increase its tearaway resistance, the freshly applied coatinghas dispersed in it some silicon carbide, marble, basalt or polyester inthe form of thin broken pieces. Any of such particles which remainpartly on the surface of such a floor covering are imbedded bypolishing.

The state of the prior art raw materials of the present invention isdisclosed in Kirk-Othmer Encyclopedia of Chemical Technology, 2nd Ed.,Vol. 1 (1963), pages 285-313, under the section Acrylic Acid andDerivatives, pages 851-882 under the section Alkyd Resins, particularlypages 865-868, wherein driers, modifiers and blending agents aredisclosed; Vol. 5 (1964), pages 679-690, under the section CoatedFabrics, particularly page 680, wherein flocked coatings are disclosed,and pages 690-716, under the section Coatings, Industrial, particularlypage 691, wherein the resume of synthetic resins used in the formulationof coatings is given; Vol. 8 (1966), pages 294-312 under the sectionEpoxy Resins, particularly pages 306-311, wherein solventless systems,amine cured coatings, ester-type coatings and structural plastics aredisclosed; Vol. 12 (1967), pages l88197, under the section Laminated andReinforced Plastics, particularly page 189, wherein fibers aredisclosed, and pages -191, wherein the plastics, catalysts and fillersare disclosed; and Vol. 16 (1968), pages 159-189, under the sectionPolyesters.

SUMMARY OF THE INVENTION Having in mind the limitations of the priorart, it has now been surprisingly found that the difficulties which havebeen encountered in the production of flocked carpets and in their useas floor coverings are avoided if the flocking with textile fibers iscarried out together with a coating operation, for example of the floor.

According to the present invention, a seamless tightly adheringduroplastic coating on a plaster, concrete, artificial stone, ornamentalor wooden base and having a carpet-like surface effect, is obtained bythe hardening of coatings of possibly colored, pigmented orfillercontaining synthetic resins on a bottom layer of twocomponentmaterials. The hardened surface layer is produced by mixing atwo-component system comprising liquid solvent-free synthetic resinswith hardeners and before the hardening, imbedding flocked-in shortlycut fibers therein. This process represents an advance over the priorart because of its reduction is the number of process steps.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The process is advantageouslyperformed by first applying upon a base of plaster, concrete, artificialstone or wood, a mixture of liquid solvent-free twocomponent syntheticresin of a viscosity between 500 and 20,000 centipoises and a hardenerby painting, rolling, spraying pouring or troweling, and then, beforethe commencement of any hardening by the hardener, electrostaticallydepositing shortly cut fibers upon the coated surface and allowing thelatter to harden.

It is also surprising that the electric conductivity of the coatingmaterial no longer requires any special attention because the coatedlayer of this invention remains adequately grounded throughout the baseon which it is deposited.

It was also not to be foreseen and was therefore surprising that in theprocess of this invention no excess of textile fibers is deposited sothat it is not necessary to remove any excess.

As base or bottom coatings, industrial or domestic plaster coatings andcementitious coatings are used, but also those containing otherhydraulic binders such as lime or gypsum, as well as bituminous orasphaltic paving materials. Other suitable materials are concrete,terrazzo, ornamental material and especially wooden floors.

By the designation solvent-free liquid twocomponent synthetic resinmaterials are to be understood all two-component materials which afterbeing mixed with the hardener will harden. They do not contain anyvolatile organic solvents which do not participate in the hardeningprocess. There can, however, be present certain solvents which do takepart in the hardening process and which will become permanent componentsof the hardened layer, as for example styrene, vinyl toluene, acrylicacid ester, methacrylic acid ester and other monomers.

Especially suitable solvent-free liquid duroplastics belong to thefollowing groups:

a. hydroxyl group containing compounds which are hardened bypolyisocyanates, such as polyethcrs, polyesters, alkyd resins, acrylateresins and epoxide resins;

b. epoxide resins which are hardenable with the help of polyamines,amidoamines or ketimines;

c. acrylic polymers and unsaturated polylesters which are hardened byperoxides in mixtures with copolymerizable monomers, such as styrene,vinyl toluene, acrylic acid ester, methacrylic acid ester and the like;and

d. those resulting from the hardening of polysulfides by the use ofheavy metal peroxides such as lead peroxide or oxides of manganese suchas manganese dioxide.

The hardener can be mixed with the two-component materials before theprocessing. It is also possible, however, for the hardener of thetwo-component material to be deposited separately upon a base by meansof a two-component spraying gun, whereupon a reaction occurs. Finally,the hardener can also be first applied to the base and then a layer ofthe two-component material deposited thereon. In each case, thehardening of the two-component material commences as soon as thehardener and the two-component material come into intimate contact witheach other.

The two-component materials are applied as clear lacquers to the base.They can, however, also be pigmented with the usual inorganic andorganic pigments, and/or mixed with fillers such as talcum, bariumsulfate, mica, asbestos, quartz, sand, etc. They can also contain theusual hardening accelerators.

The viscosity of the two-component material is between about 500 and20,000 centipoises, and it is applied to the base by the usual methodssuch as painting, roller application, spraying, casting or troweling.

The textile fibers are shortly cut fibers of different lengths andthicknesses which are applied as flocks. Suitable for this purpose arenatural fibers such as cotton, wool, preferably goat wool, but alsosynthetic fibers such as viscose flocks, triacetate flocks and polyamideflocks. The fibers are cut into lengths ranging from about 0.3 to 12 mm.

The textile fibers are flocked upon the coated surface of the base byelectrostatic methods with the help of screen radiators (ball screens)in a high voltage field or by means of electrostatic spraying devices orinstallations.

The use of the suggested two-component materials has the advantage ofpermitting a layer of sufficient thickness to be applied by a singlecoating operation, the layer being then ready to imbed the flockedtextile fibers deposited thereon and firmly hold them so that a floorcovering of this kind can be subjected to the roughest use after theresin has hardened, without loss of its carpet-like appearance. It alsoeliminates the usual troweling and smoothing of the floor which mustusually be done whenever a carpet is to be laid.

The coating of this invention is to a large extent resistant to thermal,chemical and mechanical treatment. It is surprising that such a coatingwith its fibrous surface can be cleaned with alkaline cleaning agents.In a similar manner fat-dissolving solvents such as gasoline are usedfor cleaning the coating without damage to either the textile fibers orthe resin. A more important advantage is, however, that a seamlesscoating is obtained in contrast to the polyvinyl chloride coveringswhich must be welded and the other carpet coverings which must befastened by adhesives.

It is surprising that for the coatings of this invention, onlytwo-component materials are suitable, but not single component lacquerswhich produce layers of only insufficient thickness so as to necessitaterepeated applications, each additional layer being applied only afterthe last preceding layer has dried. The solvent that must be present inthe single component coatings causes the delay.

In the process of this invention, the solvent-free liquid duroplast iscoated upon the base in layers of at least 0.5 to several mm thick. Thepreferred thickness is between about 0.5 and 5 mm. To effect itshardening, the solvent-free liquid duroplast is mixed with a hardener,or the latter is sprayed separately upon the base by means of atwo-component spraying nozzle, but simultaneously with the applicationof the liquid duroplast. The mixing of the hardener with the duroplastthen occurs during the spraying.

Within a certain time which is characteristic for each material, gellingof the solvent-free liquid duroplast coating commences. During thepreferably short time before commencement of the hardening, the flock isapplied. Upon a square meter of coated surface, not more than about 600g, preferably to 400 g of flock are applied, the exact amount dependingon the length and thickness of the fibers.

Different kinds of surface effects are produced by flocking upon theadhesive surface either cut fibers of uniform length or of differentlengths. It is also possible to deposit upon the same surface fibers ofdifferent lengths in successive operations. By the use of differentlycolored fibers, a variety of color effects is produced.

The flock covered surface hardens under the influence of hardeners withthe possible help of accelerators, even at room temperature, to producea carpetlike surface structure which is useful for covering not onlyfloors but also walls and ceilings. As a floor covering, it is extremelydurable and wear-resistant and differs from the usual floor coverings inthat it can be applied in a single combined operation.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the specification and claims in any way whatsoever.

EXAMPLE 1.

Upon a smoothed cement floor surface, by use of a trowel, a mixture isspread containing a liquid epoxide resin, a colored pigment such asyellow iron oxide, powdered quartz of particle size smaller than 150microns, and a cyclo-aliphatic polyamine as a hardener.

. The liquid epoxide resin is a known article of commerce which isproduced by reacting bisphenol-A with epichlorhydrin.

Resins of this type are sold by the Shell group under the name Epikote.The ratio of the epoxide resin to the powdered quartz is 1:13 The ratioof the epoxide resin to the amine is 5: 1.

A coating 1 mm thick is produced by spreading 2 kg of the mixture overeach square meter of floor surface. At a room temperature of 18C, thecoating will have a gelling time of two hours. Before gelling of thelayer commences, polyamide fibers cut to 2 mm lengths and of 20 denierthickness are flocked upon the epoxide resin surface through anelectrostatic ball screen. For this purpose 196 g fibers/m are used. Theresulting coating has a carpet-like surface. After 6 hours it will behard throughout and can then be walked upon, and after one week thefiber covered surface can be brushed with water and soft soap withoutdamage thereto.

EXAMPLE 2.

Upon a smoothly troweled cementitious floor a twocomponent material ofthe following composition in parts by weight is applied by means of aroller:

7.0 parts of a commerical hydroxyl group containing linear solvent-facehighly viscous liquid polyester (sold by the Bayer AG Company,Leverkusen, under the name Desmophen), with a hydroxyl content of about8.5%, an acid number of less than 2 and a viscosity at 75C of 330 i 30centipoises;

34.5 parts castor oil;

8.5 parts of a 50% paste of sodium aluminum silicate in castor oil;

22.1 parts rutile (TiO 1.5 parts yellow iron oxide;

0.4 part green chromic oxide;

25.0 parts technical homologue containing diphenylmethane-4,4-diisocyanate.

By the use of 1.5 kg of this material per m of floor surface, a layer0.8 to 1 mm thick is produced. The diisocyanate was not added until justbefore the coating step. The storage time of the mixture at 18C is 45minutes. Within this time, as described in Example 1, 205 g triacetatefibers are flocked per in of floor surface nier thickness and havingbeen cut to a length of 2.5

mm. After 3 hours the carpet-like coating which now firmly adheres tothe floor will be in condition to be walked upon.

EXAMPLE 3.

Upon a smoothed anhydrous floor a layer of hardener is coated whichbesides an acrylic styrene polymer, also contains benzoyl peroxide indibutyl phthalate. Upon this coating, by means of a spray gun, amaterial is sprayed, two-thirds of which consists of monomeric acryliccompounds and one-third of which consists of powdered quartz of 10,000mesh size. A layer 500 microns thick is formed. For that purpose 200 ghardener and 1.5 kg coating material are used per m of floor surface.The coating gels after 30 minutes at 18C. Within 15 minutes 200 gpolyamide fibers of 20 denier thickness and 2 mm length are flocked uponthe coating per in of floor surface. After 2 hours the carpet-likesurface can be walked upon and clings tenaciously to the floor.

EXAMPLE 4.

An inlaid floor is coated by means of a twocomponent spray gun with amaterial of the following composition in parts by weight:

490.0 parts of a commercial hydroxyl group containing solvent-free lowviscosity liquid branched polyether (Handbook product of the Bayer AGCompany under the trademark Desmophen), with a hydroxyl content of about1 1.5, an acid number of less than 0.5 and a viscosity at 25C of 650 icentipoises;

110.0 parts of a 50% paste of sodium aluminum silicate in castor oil;

310.0 parts heavy spar (barite);

80.0 parts titanium dioxide;

10.0 parts black iron oxide; and a hardener of 250 parts diphenylmethane-4,4'-diisocyanate (technical, homologue containing).

With a layer thickness of 1.2 mm, 2 kg per m of floor surface were used.The coating gels after one hour. Upon the still liquid layer, 200 gcotton flock of 2-3 mm length are deposited per m as in Example 1. After3 hours, the coating has hardened and can be walked upon. A carpet-likecoating has been produced.

EXAMPLE 5.

Upon a smoothed cement floor a two-component material is painted whichcontains liquid polysulfides with which a paste of lead peroxide indibutyl phthalate has been mixed. For a layer thickness of 0.8 mm, 1 kgof the material was used per m of floor surface. The coating gels atroom temperature in 30 minutes. Within this time 196 g polyamide fibersof 1.5 to 2 mm length and 15 to 20 denier thickness are flockedelectrostatically upon the still wet coating per m of floor surface.After 2 hours, the coating which then firmly adheres to the floor andhas the appearance of a carpet, can be walked upon.

1 claim:

1. In a method of providing a substrate of a synthetic resin materialwith a flocked fabric surface by applying a layer of curable syntheticresin composition comprising duroplastic cold curing synthetic resinmaterial, curing agents and accelerators directly on a concretesupporting surface, depositing fibers electrostatically on saidsynthetic resin composition when said layer is from volatile organicsolvents not participating in the in an immediate pre-gelling state andcuring said layer curing process, and having a layer thickness betweenof said synthetic resin composition, the improvement 0.5 and mm.

wherein the synthetic resin composition is a liquid free

